Many conventional semiconductor modules comprise a prefabricated housing produced using injection-molding technology and embodied as a housing frame in which the semiconductor chips are arranged. In this case, the interior of the housing frame can be potted with a silicone potting compound. Such prefabricated semiconductor modules are often mounted on high-current printed circuit boards for further interconnection. Optionally, a driver circuit board for driving the semiconductor chips situated in the semiconductor module can then also be fitted on the high-current printed circuit board. The semiconductor module and the high-current printed circuit board are firstly produced independently of one another and only later connected to one another.
In other conventional semiconductor modules, the semiconductor chips are incorporated directly into the printed circuit board. For this purpose, the printed circuit board manufacturer has to carry out the connection of the semiconductor chips to the printed circuit board, but said manufacturer normally cannot have recourse to the requisite experience, which, however, is absolutely necessary for the production of high-quality connections owing to the semiconductor chips usually having a large area. Alternatively, the connection between the semiconductor chips and the printed circuit board can also be carried out by the manufacturer of the semiconductor module. In that case, however, the printed circuit board has to be sent back to the printed circuit board manufacturer for further processing with the unprotected semiconductor chips situated on it, one or more prepreg layers being additionally applied, for example, by said manufacturer. Moreover, the terminals of the semiconductor chips that have not yet been connected to the printed circuit board have to be electrolytically coated in order to enable the semiconductor chips to be contact-connected to a further metallization layer of the printed circuit board that is to be applied. During the processing of the partly finished printed circuit board already populated with the semiconductor chip by the printed circuit board manufacturer, however, there is the risk of damage to the unprotected semiconductor chips. Moreover, applying an electrolytic coating to terminals of the semiconductor chips already mounted on the partly finished printed circuit board is very expensive on account of the required deposition thicknesses.
A further problem area is that the semiconductor chips can have very high heat densities, for example up to 200 W/cm2, such that the heat that arises is dissipated only to an insufficient extent on account of the low thermal conductivity of the epoxy resins used in printed circuit board technology (typically <1 W/mK).